Intensive self-management with frequent self-monitoring of blood glucose (SMBG) is important in type 1 diabetes to achieve
good metabolic control (1–3). Nevertheless, many patients still experience episodes of unrecognized hypo- and hyperglycemia
(4). Novel technologies for continuous glucose monitoring (CGM) that provide information about glucose excursions are now
available. Previous studies reported the benefits of retrospective evaluation of CGM data (5–11), but few assessed effects
on glycemic control (5,12–14), and only one showed improvements compared with SMBG (14). We evaluated the effect of a new
real-time glucose monitor on glycemic control in patients with poorly controlled type 1 diabetes. The device, Guardian RT
(Medtronic MiniMed, Northridge, CA), allows users to see glucose readings and set hypo- and hyperglycemic alarms and provides
trend information on changing glucose values.

Subjects were randomly assigned 1:1:1 for 3 months to Guardian RT continuously (arm 1) or biweekly for 3-day periods every
2 weeks (arm 2) or to continue conventional SMBG (control). Treatment adjustments made by physicians and patients were based
on SMBG profiles in control subjects and on real-time glucose profiles in arms 1 and 2. Patients were instructed to perform
confirmatory SMBG measurements before therapeutical interventions or corrective action if hypo- or hyperglycemic alarms or
symptoms occurred. …